Drill-holding chuck-bolt for rock-drills.



Patented uly l5, I902.v

0. H, BOSSEBT. DRILL HOLDING CHUCK BOLT FOR ROCK DRILLS.

(Application filed. Feb. 11, 1902.)

(No Model.)

ZZZ/673607" Unrrnn STATES PATENT OFFICE.

OTTO HENRY BOSSERT, OF DENVER, COLORADO.

DRILL-HOLDING CHUCK-BOLT FOR ROCK-DRILLS.

SPECIFICATION forming part of Letters Patent No. 704,502, dated July 15,1902. Application filed February 11,1902. $erial No. 93,560. (No model.)

To CLZZ whom, it may concern:

Be it known that I, Or'ro HENRY BOSSERT, a citizen of the United Statesof America, residing at Denver, in the county of Arapahoe and State ofColorado, have invented certain new and useful Improvements in Chucksfor Rock-Drills; and I do declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledinthe art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to the letters of reference markedthereon, which form a part of this specification.

My invention relates to improvements in drill-holding chuck-bolts forrock-drills.

The object of the invention is to provide means for rigidly clamping adrill within the chuck of a drill-bar in such a manner that the same maybe quickly removed and replaced when desired, and to this end I dispensewith the nuts which in general practice are secured upon the ends of theordinary clamping or U bolt and employ a yoke provided with a pair ofholes, through which the ends of the bolt pass, and a keyway, whichpasses through the" yoke at right angles to the said bolt-holes in sucha manner as to intersect them. A key is slid into the keyway, the sidesof which engage notches in the bolt, and thus secure the yoke upon thesaid bolt, so that when a suitable wedge is driven between the top ofthe bolt and the ordinary clamping-block, which rests upon the end ofthe drill, the said drill will be rigidly secured within the chuck, andto remove the same it is only necessary to knock the wedge to one sideby a blow from a hammer, when the drill may be removed, and whenreplaced a blow on the opposite end of the wedge will tightly clamp thesaid drill.

The invention further consists in certain novel features ofconstruction, as will be set forth in the accompanying specification andclaims.

In the accompanying, drawings, Figure 1 is a perspective view of thechuck of a drill; shaft and showing the drill clamped therein by theemployment of my improved device. Fig. 2 is'a vertical transversesectional view of the same at the point where the clampingbolt passesthrough. Fig. 3 is a vertical longitudinal sectional View through thechuck and clamping device, fully illustrating the manner of clamping thedrill. Fig. 4 is a plan view of the clamping device detached. Fig. 5 isa perspective view of the clamp-block. Fig. 6 is a perspective view ofthe yoke used in connection with myimproved device. Fig. '7 is a view ofa modification thereof. Fig. 8 is a, view of a split pin used inconnection with the said modified form of yoke.

Referring to the drawings, the letter A indicates the drill-bar, and Bthe chuck, which is integral therewith. The chuck is provided with theusual longitudinal bore'b, in which the end of the drill lies, and onits upper side with the opening biwhich communicates with the saidlongitudinal bore, as will be understood, and on either side of theopening I) are the usual bolt-holes 11 through which the members of theU-bolt as commonly used are passed. 1

In common practice a drill is clamped in the chuck in the followingmanner: The rear end of the drill is placed in the bore 1). Aclamp-block is then placed in the opening b so as to rest upon the endof the drill, and the U-bolt is passed through holes 12 so as tostraddle the clamp-block,and upon the threaded ends of the said bolt arescrewed nuts by which the bolt is drawn upon the clampblock, which isthus caused to tightly clamp the end of the drill and hold the samewithin the chuck. By the employment of my improved device the nuts aredispensed with,

and the drill is clamped in the following manner: The rear end of adrill C is passed into the bore 2) of the chuck B, and a clamp-block Dis placed in the opening b so that a semicircular groove (1 in its underside will overlie the end of the drill. Aspeciallysconstructed U-bolt Eis then passed down through the chuck, its members lying in verticalsemicircular grooves d on each side of the block D, as shown. Near thelower end of each member of the U-bolt and on the inner side thereof isa notch or recesse, the object of which will presently appear. A yoke F,having vertical holes f and a keyway f at right angles to the holescutsoas tointersect each hole on its inner side, is then slipped uponthe ends of the bolt E, the said ends passing through the holes f, asshown, and when the ICO keyway f therein registers with the notches orrecesses e in the members of the bolt E a vkey G, which is slightlywider at one end than at the other, is passed through the said keyway fand recesses 6, thus securely locking the said yoke upon the lower endof the bolt. A wedge H is then placed between the top of block D and theconnecting member of the bolt E and is driven forward, so as to tightlyclamp the said block against the end of the drill, thus holding the samesecurely within the chuck. The point of wedge H and the narrow end ofkey G are both toward the forward end of the drill. Thus the jar fromthe stroke of the drill will serve to retain the said wedge and key inthe positions to which they were driven when the drill was clamped.

By the employment of the herein-described device a drill can be quicklyand firmly secured within the chuck of the drill-bar, and ablowfromahammeron the forwardend of the wedge will unclamp the parts and allowsaid drill to be removed, while with the device now in general use a nuton each end of the bolt must first be unscrewed before the drill can beremoved or tightly screwed up before the drill is securely clamped, andmuch time is thus consumed, for in drilling very hard rock the drillsare so dulled and must be replaced by sharp ones, and while in the oldform the nuts are apt to work loose from the constant jar upon them thesame jar when my improved device is used serves to more tightly set theclamping-wedge.

' In Fig. 7 I have shown a modification of the yoke F, 'in which thekeyway f is dispensed wit h and two holes f are drilled horizontallythrough the yoke or at right angles to the holes f, each holefintersecting one of the holes f, as shown. The yoke is placed on thelower end of the bolt in such a position that the holes f will be inline with the recesses e in the bolt, when a pin f having a'splitf inits free end, is passed through each hole and recess, and the end ofsaid pin is spread toprevent it from becoming detached from the yoke,and thus the yoke may be locked upon the bolt.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a drill-holder for rock-drills, the combination with a drill anddrill-chuck, of a U-shaped bolt, the members of which pass through holesin the said chuck and are each provided with a notch or recess neartheir lower end; a yoke having holes through which the depending ends ofthe bolt are passed, and a keyway at right angles to the said holes,which intersects the same; a key which is passed through the keyway insaid yoke and through the notch or recesses in the depending members ofthe bolt, so as to lock the said yoke upon the said bolt, and a wedgewhich lies between the connecting members of said U -shaped bolt and thetop of the aforesaid clamp-block the said wedge being designed, whendriven in one direction, to clamp the said block upon the aforesaiddrill, so as to hold the same within the chuck, substantially as shown.

2. In a drill-holder, for rock-drills, the combination with a drill anddrill-chuck, of a clamp-block which fits in a recess, in the said chuck,the said block being provided on its under side with a semicircularrecess which overlies the end of the drill; a U-shaped bolt, whichstraddles the said block, the members thereof passing through the saidchuck and each of said members being provided with a groove or recessnear its lower end; a yoke having vertical holes and holes at rightangles to the said vertical holes, which intersect the same, the saidyoke being adapted to fit 'on the depending ends of the U-shaped bolt;

pins which pass through the last-mentioned holes in the said yoke, andthrough the grooves or recesses in the ends of the said U-shaped bolt soas to lock the said yoke upon the said bolt, and a wedge which is drivenbetween the connecting member of the U-shaped bolt and the top of theaforesaid clamping-block, so as to clamp the said block upon the end ofthe aforesaid drill, to retain the same within the said chuck,substantially as shown.

3. A clamping device for drills and the like, consisting of a U-shapedbolt, the members of which are each provided with a groove or recessnear their lower end; a yoke, having holes through which the members ofthe bolt pass, and a keyway at right angles to said holes, whichintersect the same; a key which is passed through the said keyway, andthrough the grooves or recesses in the members of the bolt, so as tolock the said yoke upon the said bolt a clamping-block, which lies uponthe drill or a like object, and a wedge which is driven between the saidblock and the connecting member of the bolt, in combination with anysuitable chuck or casing, substantially as shown.

In testimony whereof I affix my signature in presence of two witnesses.

OTTO HENRY BOSSERT.

Witnesses:

G. SARGENT ELLIOTT, HIRAM W. OONGER.

